Salvador Nava Martinez, 78, a veteran opposition leader who fought against Mexico's one-party rule for more than three decades and who had twice served as mayor of the central Mexican city of San Luis Potosi, died of cancer May 18 at his home there.

Dr. Nava, who was dubbed "the Mexican Gandhi" by the opposition press, won nationwide recognition for the tenacity of his struggle against the long-ruling Institutional Revolutionary Party (PRI).

After visiting him 10 days before his death, Mexican President Carlos Salinas de Gortari praised his opponent's 34-year campaign for democracy and human rights and said that Dr. Nava "was a ceaseless, nonviolent fighter for democracy."

Dr. Nava ran twice as an independent candidate for governor of the state of San Luis Potosi, losing both times because of what he and his supporters claim was vote-rigging and fraud by the PRI.

In 1961, the Mexican army occupied San Luis Potosi for three months -- and jailed Dr. Nava in Mexico City -- to crush protests against the alleged fraud that deprived him of the governorship.

Backed by his center-right National Action Party, Dr. Nava ran again last October for governor. Fausto Zapata Loredo of the governing PRI was named winner, which sparked protest marches by Dr. Nava and his party. Partially as a result of the protest campaign, Zapata resigned under presidential pressure.

The sudden resignation -- the third of a San Luis Potosi governor attributed to Dr. Nava's popularity -- ended a protest march that the opposition leader began 12 days earlier on Mexico City. But Dr. Nava was denied the governorship. A local PRI leader and close associate of the president was named interim governor to replace his disgraced opponent, pending elections.

Dr. Nava was an ophthalmologist by training and profession. He taught at the local university and opened a clinic in San Luis Potosi to treat factory, railroad and electrical workers.

STEVEN M. AUERBACH

Writer and Lawyer

Steven M. Auerbach, 46, a writer and lawyer who had worked as an editor for the Bureau of National Affairs, died May 18 at Fairfax Hospital from complications of a heart transplant operation he underwent six months ago.

He joined the BNA in 1970. He was an assistant editor, chief legal editor, and then, from 1977 to 1983, managing editor of its Patent, Trademark and Copyright Journal. Since 1983, he had served on the journal's advisory board and had worked on independent writing projects.

Mr. Auerbach, who lived in McLean, was a New York native. He was a graduate of the State University of New York at Buffalo and its law school. He came to the Washington area in 1969 and was a staff attorney with the Justice Department before joining the BNA.

Survivors include his wife, Dr. Anita Weiss Auerbach of McLean; his mother, Mildred Theis of Rockville Centre, N.Y.; and a sister, Susan Scherr of Potomac.

MILDRED M. LYMAN

Army Awards Administrator

Mildred McBride Lyman, 78, a retired incentive awards administrator for the Army's engineering center at Fort Belvoir, died of a blood disorder May 17 at Mount Vernon Hospital. A resident of the Washington area since 1955, she lived in Alexandria.

Mrs. Lyman retired in 1973 after 18 years at Fort Belvoir. Earlier, she worked at the Social Security Administration in East St. Louis, Ill.

She was born in Ava, Ill.

She was former secretary of the Women's Society of Cameron United Methodist Church in Alexandria and a trustee of the Mount Vernon chapter of the American Association of Retired Persons.

Her husband, Harry L. Lyman, died in 1986. Survivors include two children, Wendy Lyman Ryan of Silver Spring and Judith Lyman Vincent of Walton, Neb.; two sisters, Carrie Nickell of Belleville, Ill., and Zuma Bill of Newport News, Va.; seven grandchildren; and six great-grandchildren.

JOANNE REMUS

College Student

Joanne Remus, 27, a former student at George Mason University who also had been senior supervisor of financial reporting for the Student Loan Marketing Association in Herndon, died of cancer May 17 at Fairfax Hospital.

Miss Remus, who lived in Fairfax, was born in Seoul. She came to the United States as an infant and had lived in the Washington area since 1971. She graduated from W.T. Woodson High School in 1982.

She worked at the Student Loan Marketing Association from 1986 to 1990, when she left to become a full-time student at George Mason.

Survivors include her parents, Edward and Kim Remus of Fairfax; a sister, Jeanne Remus Gruenburg of Culpeper; and two brothers, Joseph Remus of Burke and Thomas Remus of Fairfax.

GWLADYS LEONARD BROWN

Teacher

Gwladys Owen Leonard Brown, 90, a former teacher, died of congestive heart failure May 17 at Sibley Memorial Hospital. She had lived in Washington for more than 40 years.

Mrs. Brown, a native of Whitesboro, N.Y., attended Antioch College. She taught at a girls' school in Kansas City in the 1920s and 1930s and then accompanied her first husband, Army Col. Joseph Leonard, to posts in the United States.

She was a member of the Womens' Association of National Presbyterian Church, the Welsh Society of Washington, the Washington Club, Cosmos Club, Army & Navy Club, and the Women's National Republican Club.

Col. Leonard died in 1962. Mrs. Brown's second husband, retired Army Col. Carey Brown, died in 1984. She leaves no immediate survivors.

MARY LOU TUMIN

Civic Activist

Mary Lou Tumin, 63, a former Bethesda resident and past president of the Old Georgetown Road Citizens Association, died of cancer May 14 at a hospital in Sanford, Fla. She lived in Sanford.

Mrs. Tumin, who was born in Erie, Pa., was reared in Washington. She lived here until moving to Florida from Bethesda in 1979. She was a graduate of Wilson High School and a 1951 business administration graduate of the University of Maryland.

She was a member of Gamma Phi Beta social sorority.

Survivors include her husband, Alfred, of Sanford; three sons, Alfred Jr., of Altamonte Springs, Fla., Kenneth, of Sanford, and Bruce, of North Lauderdale, Fla.; a brother, retired Navy Capt. Arthur W. Motley of Virginia Beach; and a granddaughter.

FRANCES B. SIMMINGTON

Quality Assurance Officer

Frances Belinda Simmington, 41, a quality assurance officer at St. Elizabeths Hospital, died May 18 at Doctor's Hospital in Lanham after a heart attack.

Mrs. Simmington, who lived in Lanham, was born in New York and graduated from Hunter College. She received a master's degree in nursing from Catholic University.

She had been on the staff at St. Elizabeths Hospital for about 10 years. Earlier, she had taught nursing at Albany State University in Georgia and at the University of the District of Columbia. She had lived in this area since about 1975.

She was a member of New Life Assembly of God Church in Capitol Heights.

Survivors include her mother, Eula Simmington, and a sister, Therese Simmington, both of Lanham.

MELISSA H. LINDSAY

Merchant

Melissa Howe Lindsay, 42, a partner in the Washington women's apparel shop Pinnacle, died of breast cancer May 17 at Georgetown University Hospital.

Mrs. Lindsay was a fifth-generation Washingtonian. She graduated from Madiera School and Ohio State University. She had been a business partner in the Pinnacle for about 3 1/2 years.

She was a member of St. Alban's Episcopal Church in Washington.

Her marriage to John R. Lindsay ended in divorce.

Survivors include two children, Jennifer Howe Lindsay and Paul Andrew Lindsay, both of Washington; and two sisters, Susan H. Thorn of Cross River, N.Y., and Elizabeth H. McAlpin of Morristown, N.J.

MARY D. SCHELTEMA

University Instructor

Mary Detwiler Scheltema, 56, a writing instructor at the University of Maryland for 10 years, died of cancer May 17 at Suburban Hospital. She lived in Kensington.

Mrs. Scheltema, who was born in Atlanta, came to the Washington area in 1943. She was an honors graduate of the University of Maryland, where she also received a master's degree in English.

Survivors include her husband, Walter R., of Kensington; two sons, Willem, of Washington, and James, of Silver Spring; a daughter, Mary Dreyer of Charlottesville; her mother, Hazel Detwiler of Silver Spring; a brother, Donald Detwiler of Carbondale, Ill.; and three grandsons.